WAEC Chemistry Past Questions & Answers - Page 159

791.

Which of the following methods can be used to separate a mixture of two miscible liquids with different boiling points?

A.

Decantation

B.

Distillation

C.

Evaporation

D.

Filtration

Correct answer is B

No explanation has been provided for this answer.

792.

From the following ores is iron extracted? I. Haematite ll. Bauxite III. Magnetite IV. Cassiterite

A.

l and ll only

B.

l and lll only

C.

l, ll and lll only

D.

l, ll, lll and lV

Correct answer is B

No explanation has been provided for this answer.

793.

Glucose reduces Fehling's solution on warming to

A.

copper (l) oxide

B.

copper (ll) oxide

C.

copper (l) chloride

D.

copper (ll) hydroxide

Correct answer is A

No explanation has been provided for this answer.

794.

Which of the following compounds reacts readily with sodium to liberate hydrogen?

A.

CH3CH2CH3

B.

CH3COOH

C.

CH3 CH2CHO

D.

CH3 CH(OH)CH3

Correct answer is B

No explanation has been provided for this answer.

795.

Consider the reaction below: Vegetable oil \(\frac{H2;NI catalyst}{High temperature}\) product. The reaction is applied in the manufacture of?

A.

drugs

B.

margarine

C.

paraffin wax

D.

soapy detergents

Correct answer is B

This is called hydrogenation. It includes the manufacture of margarine from animal or vegetable fats and oils.

Ethene reacts with hydrogen in the presence of a finely divided nickel catalyst at a temperature of about 150°C. Ethane is produced.